Percorrer por autor "Peleteiro, Mercedes"
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- Beyond DNA removal: assessing the immunological response to decellularized rabbit dermal matricesPublication . Rosadas, Marta; Sánchez Espinel, Christian; Peleteiro, Mercedes; Sousa, Alda; Ribeiro, Viviana P.; González-Fernández, África; Oliveira, Ana L.Introduction: Decellularized matrices have attracted considerable attention in tissue engineering and regenerative medicine due to their ability to preserve the biochemical composition and microarchitecture of native tissues. Although DNA removal is commonly used as the main indicator of decellularization efficiency, other factors—such as endotoxin contamination, damage-associated molecular patterns, and residual reagents—can significantly influence the host immune response. In this study, decellularized rabbit dermal matrices (dRDM) produced using two different protocols— resulting in DNA levels below or above the proposed safety threshold of 50 ng/mg dry tissue—were evaluated for their immunological performance. Conclusions: Two decellularization protocols produced dRDMs with distinct biological profiles. Although the SDC 3H protocol achieved DNA levels below the recommended threshold, it was associated with greater collagen degradation, whereas the SDC 30 min protocol better preserved native dermal collagen. Both matrices were sterile, endotoxin-free, and did not induce ROS production in PBMCs. However, dry dRDMs and SDC 3H-treated matrices promoted complement activation and increased PBMC necrosis. Overall, despite not meeting the recommended DNA threshold, the SDC 30 min protocol demonstrated superior immunocompatibility and collagen preservation, highlighting that DNA content alone is not a reliable predictor of decellularization efficiency. Instead, immunocompatibility, collagen integrity, physical cell–matrix interactions, and potential detergent residues play a critical role in defining matrix performance.
- A new bioactive dermal substitute for wound healing and skin regenerationPublication . Rosadas, Marta; Sousa, Teresa; Reis, Mariana; Sousa, Clara; Sousa, Alda; Sánchez Espinel, Christian; Peleteiro, Mercedes; González-Fernández, África; Ribeiro, Viviana P.; Oliveira, Ana LeiteAim: Rabbit skin is an abundant agri-food by-product with interesting properties to be up-cycled into a xenogeneic dermal substrate for skin and regeneration. When decellularized, rabbit dermis preserves collagen–elastin components that can guide cell behavior. However, decellularization conditions can also influence the preservation of tissue architecture and may introduce immunogenic triggers such as damage-associated molecular patterns (DAMPs). This work aimed to develop low-immunogenicity decellularized dermal matrices (dDMs) using rabbit skin as by- product. Method: dDMs were generated using optimized chemical decellularization protocols and evaluated for structural and biochemical integrity using SEM, tensile testing, FTIR, proteomics, and DNA, GAGs, collagen, and elastin quantification. Immunogenicity was assessed throughendotoxin analysis and by exposing human peripheral blood mononuclear cells (PBMCs) to the matrices to measure complement activation, ROS, apoptosis, activation markers, and cytokine release. The ability of dDMs to support human dermal fibroblasts (hDFs) and keratinocytes (HaCaTs) was examined over 14 days using Alamar Blue, BrdU, SEM, and DAPI/phalloidin staining. Results/Discussion: dRDMs preserved native collagen–elastin architecture, and GAG levels were comparable to human dermis. Residual DNA confirmed effective decellularization. No significant immune activation occurred: ROS and apoptosis were absent, and PBMC activation matched controls with only mild monocyte and B-cell responses. Cytokine release indicated modest inflammatory signaling induction. Interestingly, matrices with lower DNA content triggered stronger immune responses, suggesting biocompatibility is influenced more by processing-related factors (detergent residues or DAMPs) than by DNA levels. hDF and HaCaT adhesion, viability, and proliferation were maintained for 14 days. Conclusion: dRDMs showed favorable structural, biochemical, and immunological profiles and supported dermo-epidermal cell growth, demonstrating potential as bioactive dermal substitutes for skin regeneration.
- A novel ECM platform for skin regeneration: balancing structural integrity with low immunogenicityPublication . Rosadas, Marta; Sousa, Teresa; Sousa, Alda; Sánchez Espinel, Christian; Peleteiro, Mercedes; González-Fernández, África; Ribeiro, Viviana P.; Oliveira, Ana LeiteRabbit skin is an abundant agri-food by-product which can be up-cycled for generating xenogeneic extracellular matrix (ECM) scaffolds for skin tissue engineering, regeneration and modelling. When decellularized, rabbit dermis can preserve native collagen–elastin architecture and bioactive cues that support cell behaviour. However, decellularization parameters strongly influence ECM preservation, and trigger residual immunogenic components such as damage-associated molecular patterns (DAMPs). Decellularized rabbit dermal matrices (dRDMs) were produced using optimized chemical decellularization protocols and evaluated for decellularization efficiency, physicochemical properties and biochemical composition, using SEM, tensile testing, FTIR, proteomics, DNA, GAGs, collagen, and elastin quantification. Immunogenicity of dRDMs was assessed by endotoxin evaluation and using human peripheral blood mononuclear cells (PBMCs) to measure complement activation, ROS, apoptosis, activation markers and cytokines. dRDMs capacity to support human dermal fibroblasts (hDF) and keratinocytes (HaCaTs) adhesion and proliferation was assessed for 14 days, via Alamar Blue, BrdU, SEM, and DAPI/phalloidin staining. The dRDMs preserved native collagen and elastin networks. GAGs content was comparable to human dermis. DNA remained <50 ng/mg dry tissue, indicating efficient decellularization. No significant immune activation occurred: ROS and apoptosis were absent. PBMC activation matched controls with mild monocyte/B-cell responses. Cytokine profiles revealed modest inflammatory signaling with IL-10 production. Notably, lower DNA matrices induced stronger immune response, suggesting that biocompatibility depends on processing factors like detergent residues or DAMPs rather than DNA alone. In vitro, hDF and HaCaT viability and proliferation were maintained for 14 days on dRDM, supporting its potential for dermo-epidermal reconstruction in advanced co-culture models. Overall, dRDMs exhibited structural, biochemical, and immunological features supporting their potential as a robust dermal substrate for skin tissue engineering.